DE 44 36 397 A1 relates to a device for the aftertreatment of exhaust gases. According to this solution, a reducing agent is introduced into the exhaust gas which is fed to the catalyst. The introduction is carried out in this case via an electrically controlled metering valve which is combined with a control valve in a common housing. The control valve serves for the controlled introduction of supplied pressurized air, in which a quantity of reducing agent, which is received via the metering valve, is processed and intermittently introduced into the exhaust gas. As a result, urea deposits and agglutinations on the metering valve and control valve can be avoided and an optimum processing of the introduced reducing agent can be achieved.
US 2010 0313553 relates to an injector for exhaust gas aftertreatment, which introduces an urea solution for lowering NOx emissions in an exhaust gas system. In this case, the injection end of the injector is enclosed by an inner housing and an outer housing. A gap which results between the inner housing and the outer housing serves as a temperature barrier. The outer housing is of nozzle-like design and allows the mounting of the injector inside an exhaust gas pipe by means of a flange.
U.S. Pat. No. 5,647,316 relates to an injector device for an internal combustion engine for introducing a pressurized fluid into a cylinder space. The injector in this case comprises a first valve and a second valve. Whereas the first valve serves for injecting fuel, the second valve serves for introducing an auxiliary substance, for example water or a urea solution. The second valve is operated by means of a valve element. This valve element is hydraulically actuated via a hydraulic line. A drainage line, by means of which surplus hydraulic fluid can be drained off and fed to a tank, is located on the valve element.
DE 10 2009 047 375 A1 relates to a metering module with fluid cooling. Disclosed there is a device for cooling a metering module, especially for the metered feed of a reducing agent into the exhaust gas tract of an internal combustion engine. A cooling device, through which flows a cooling fluid, is associated with the metering module. A generated surface of the metering module is enclosed by a cooling body through which flows a cooling fluid.
A disadvantage of known active cooling solutions is the absence of cooling effect in the upper region, especially in the electrical contact region of an injection valve of the metering module. As a result, there is no possibility of using the metering module at an ambient temperature level above 160° C. The electrical plug-in connector and the coil of the injection valve can suffer damage at a temperature level which lies above 160° C.